The partner of murder victim Sadie Hartley was swapping sexually explicit texts with her alleged killer 10 days before she died, a court heard on Thursday.

Ian Johnston, 57, broke down in tears as the jury heard of his on-off affair with Sarah Williams, 35.

He admitted they had swapped “as many as 30 or more” texts, including naked photographs of each other, up until January 4 this year.

Mr Johnston said he first met Williams in December 2012 on the indoor ski slopes of Manchester’s Chill Factore complex and they started a relationship.

He said: “It was very quick. There was no dating. She would turn up at my house ... and arrived in a short skirt and red high heels.”

During this time he was also involved in an “intermittent” relationship with communications director Ms Hartley.

Businesswoman Sadie Hartley (Image: Lancashire Police/Daily Mirror)

In 2013 Mr Johnston, a ski instructor, said he had tried to finish his relationship with Williams and in October that year he and Ms Hartley travelled to Ecuador for a 22-day trip.

In December the pair went on a skiing holiday and stayed at the same hotel as Williams and her partner, David Hardwick, 75, but he said Ms Hartley was not aware of his relationship with Williams at that time.

The following September, Ms Hartley received an anonymous letter in which a woman boasted of the “fantastic” sex she was having with ex fireman Mr Johnston.

And the next day Williams arrived at his home wearing a short skirt and red high heels.

He said: “I tried to stop her in the doorway. She physically tried to move me out of the way to get in. I was very aware I had to restrain her and I didn’t want to hurt her.

“She was shocked at me not letting her in. She appeared shocked that I knew about the letter, the letter was anonymous.”

He added: “She left shouting and screaming and walked down the road with her high heels in her hands.”

Sarah Williams, 34, who has been identified as the woman arrested for the murder of Sadie Hartley

In November 2014 Mr Johnston started living with Ms Hartley.

But Williams continued to send him messages and in December last year explicit texts and photographs were exchanged between the pair.

More explicit photographs followed, including one sent by Williams on Christmas Day.

It was accompanied by the message: “Good morning, my lovely. Merry Christmas. Hope this is something nice to look at and make you smile.”

On January 4 - some 10 days before the murder - more explicit photographs were messaged from Williams and “a similar response” received from Mr Johnston, the jury heard.